The types of mass spectrometry are an electro-spray ionization mass spectrometry and a matrix-assisted laser desorption/ionization mass spectrometry (MALDI). A surface-enhanced laser desorption/ionization (SELDI) method employing MALDI is representative as the technology of applying the mass spectrometry to the chip surface. However, in recent, secondary ion mass spectrometry (SIMS) has been known to be suitable for reproducible analysis in a low mass range since it does not use a matrix as compared with MALDI, and has been reported to be very accurate and sensitive in surface analysis at a level of several nanometers. In addition, it has been known to be very effective for quick scanning and mass analysis imaging, and thus, application thereof to analyze a biochemistry material will be expected to double the applicability thereof.
However, the secondary ion mass spectrometry has difficulty in directly analyzing a biochemical material on a chip surface due to the currently limited mass measurement range (approximately within 200 Da) thereof as compared with MALDI, and in order to overcome this, various secondary ion amplification methods have been proposed (Wu, K. J.; Odom. R. W. 1996, Anal. Chem. 68, 873-882; McArthur, S. L.; Vendettuoli, M. C., Ratner, B. D. and Castner, D. G, 2004, Langmuir 20, 3704-3709). For example, there has been introduced cationization by alkali ions or a method of increasing secondary ions through coating of the gold thin film, and recently, there is an effort to improve secondary ion efficiency using a polyatomic ion gun. In addition, U.S. Patent Laid-Open Publication No. 2008-0076676 provides a technology of using a gold nano particle as a signal amplifier. However, the above technology may have difficulties when being directly applied to bio-chips since signal improvement capability is still low and surface reproducibility is insufficient.